Adverse health effects of cigarette smoking on pregnancy outcomes are significant and costly. Despite the well-publicized risks, almost one-quarter of women continue to smoke throughout pregnancy. Further, women from disadvantaged backgrounds are over-represented among pregnant smokers. Innovative smoking cessation interventions are needed to increase quit rates in pregnant smokers, particularly in low socioeconomic populations. The proposed study evaluates the feasibility and efficacy of theoretically innovative prenatal smoking cessation intervention based on Motivational Enhancement Therapy (MET). A randomized, controlled, pretest/posttest, between groups design will be employed to compare MET with usual care for reducing smoking rates among pregnant women. Sixty-seven pregnant smokers, at least 16 years of age and attending a university-based, public clinical will be assigned to each of the two groups. In addition to achieving higher abstinence rates, we expect that the MET intervention will produce significant changes in several domains of function (e.g. coping, self- efficacy, readiness to change). Smoking outcomes will be assessed via objective (saliva cotinine analyses) and self-report measures. Logistic regression procedures will be used to examine posttreatment smoking group differences. Repeated measures analysis of variance will be used to evaluate treatment related changes in other domains of functioning. MET strategies and techniques are implemented using an empathic, non- confrontational yet directive counseling style to enhance motivation and reduce ambivalence about change. The MET intervention consists of four counseling sessions and one stages of change based, personalized feedback letter delivered over 8-weeks. The first counseling session will occur at the clinic during a woman's first prenatal visit with the three subsequent sessions being conducted by telephone. Therapy manuals, trained counselors, competency checks, and adherence rating scales will be used to verify treatment fidelity. This research will contribute important theoretical and empirical information concerning the efficacy of a new and innovative intervention for pregnant smokers and will provide the basis for larger effectiveness trials.